The present application references U.S. Pat. No. 6,612,455 to inventor Byrne entitled Cap Lock for Assembly and System.
Byrne's cap lock for assembly and system can be used to assist maintenance of proper refrigerant charge and airflow for the life of air conditioners.
Some studies show approximately 50 to 67 percent of air conditioners suffer from improper refrigerant charge and airflow, and this reduces efficiency by approximately 10 to 50 percent (“National Energy Savings Potential from Addressing HVAC Installation Problems,” US Environmental Protection Agency, 1998; “Assessment of HVAC Installations in New Air Conditioners in the Southern California Edison Service Territory,” Electric Power Research Institute, 1995; “Enhancing the Performance of HVAC and Distribution Systems in Residential New Construction,” Hammarlund, J., et al. 1992 ACEEE Summer Study on Energy Efficiency in Buildings. “Field Measurements of Air Conditioners with and without TXVs,” Mowris, R., Blankenship, A., Jones, E., 2004 ACEEE Summer Study on Energy Efficiency in Buildings, August 2004).
Potential savings in the United States from proper refrigerant charge and airflow are approximately 19.6 Billion kilowatt-hours per year and electricity demand savings are approximately 10.3 Million kilowatts. Most air conditioning technicians do not have proper training, equipment, or verification methods to ensure proper refrigerant charge and airflow. Instead, technicians rely on rules of thumb such as “add refrigerant until suction line is 6-pack cold or suction pressure is 70 psig or liquid pressure is less than 250 psig.” Air conditioners either do not receive regular service or they are serviced periodically and overcharged due to organizational practices of adding refrigerant charge until the suction line is “6-pack cold.” This practice causes air conditioners to be overcharged and operate inefficiently.
Some prior art methods involve taking measurements of certain temperatures and pressures of a cooling system and determining if the system either needs refrigerant added or removed. A significant drawback to these methods is that no measure of the amount of refrigerant to be added or removed is known. Instead, the technician must add or remove incremental amounts of refrigerant. With each incremental iteration, the system must be operated and stabilized, typically for fifteen minutes or more, before another set of readings can be taken to determine if the system is now running in an efficient manner. The time involved with this haphazard iterative method results in an unnecessary cost to the consumer. What is called for is a system and method for the diagnosis of air conditioning systems that determines an amount of refrigerant to be added or removed without iteration.
Correcting overcharged systems with improper airflow saves electricity by reducing refrigerant pressure and proportionally reducing electric power usage. It also eliminates problems of liquid refrigerant returning to the compressor causing premature failure. Correcting undercharged air conditioners with improper airflow saves electricity by increasing capacity allowing them to run less which extends the life of the compressor. It also prevents overheating of the compressor and premature failure.
The present invention relates, in part, to a method for verifying proper refrigerant charge and airflow for split-system and packaged air-conditioning systems and heat pump systems in cooling mode to improve performance and efficiency and maintain these attributes over the effective useful life of the air conditioning system.
In particular, the method may be suitable for determining proper R22 and R410a refrigerant level and airflow across the evaporator coil in air-conditioning systems, which are used to cool residential and commercial buildings. The method includes in-operation diagnostic measurements with the compressor and indoor fan switched on. The diagnostic system records site information, air conditioner information, measurement equipment calibration information, measurements used in the algorithms to make predictive recommendations, refrigerant charge and airflow adjustments, and verification data using: 1) personal digital assistant Expert-system Software (PDAES) software; 2) Telephony Expert-system Software (TES), deploying Interactive Voice Response (IVR) technologies; 3) personal computer (PC) software; and 4) internet database software, accessed via a web-based browser interface.